another question...is this information about testosterone function full? or have i missed out something?

The interstitial cells in the testes produce and secretes the male sex hormone Testosterone. Testosterone is responsible for the development of secondary male sex characteristics also called the androgenic functions of testosterone. Some examples of these characteristics of this Testosterone is increased growth of body hair, beard growth, deep voice, growth of the Adam’s apple, shoulders widen and rib cage expands, increased production of sebaceous glands, development of the penis, aggressiveness, sexual behavior, libido, and the maturation of sperm. Testosterone accelerates muscle buildup, increases the formation of red blood cells, speeds up regeneration, and speeds up recovery time after injuries or illness. This Testosterone also stimulates the entire metabolism which results in the burning of body fat.